The present invention relates to broadcast teleservices for mobile communications networks and more particularly to a method for delivering broadcast teleservice messages over packet data networks.
In a conventional mobile communication network, a mobile terminal must register with the network in order to receive services. The mobile communication network typically provides voice services, but may also include more advanced services such as short message services (SMS), data services, and broadcast teleservices. Data services allow users to send and receive data, such as facsimile data, over wireless communication channels. SMS allows a user to send and receive short text messages. Broadcast teleservices allow a user to receive messages that are broadcast over a geographic area to all users or to a group of users. Broadcast teleservices are used, for example, to broadcast weather forecasts, sports scores, news, and other information to mobile terminals.
The Telecommunications Industry Association/Electronic Industry Alliance (TIA/EIA) has developed a protocol to provide transport for broadcast teleservices, which has been incorporated into its standard for PCS/Cellular Systems (known as TIA/EIA-136). This protocol is known as the Broadcast Air Interface Transport Service (BATS). BATS allows a mobile terminal camped on a digital control channel (DCCH) to receive broadcast teleservice messages. To briefly summarize, the forward DCCH includes a logical channel, called the Broadcast Control Channel (BCCH), that carries broadcast teleservice messages. The BCCH comprises three sub-channels—the Fast Broadcast Control Channel (F-BCCH), the Extended Broadcast Control Channel (E-BCCH), and the SMS Broadcast Control Channel (S-BCCH). The F-BCCH and E-BCCH carry system-related information and operating parameters needed to mobile terminals to acquire and maintain service on the network. The S-BCCH carries SMS messages and other broadcast teleservice messages. A BATS-specific protocol includes functions for assigning and announcing sub-channels of the S-BCCH that carry specific types of broadcast teleservice messages. For example, different sub-channels may be defined to carry weather, new, sports scores, etc. This protocol allows mobile terminals to receive the desired broadcast teleservices in which the user has an interest.
Data services are also becoming more popular and demand for such services is growing rapidly. As demand for data services grows, mobile communication service providers are moving from circuit-switched networks, which were originally designed for voice communications, to packet-switched networks, which are better suited for data communications.
In a circuit-switched (CS) network, the communication path between the originating and terminating users is fixed for the entire duration of the call. That is, the mobile switching center (MSC) dedicates a voice channel connection between the calling party and called party for the entire duration of the call. A call-setup procedure is required to allocate network resources. Since the transmission path is fixed, data arrives at the final destination in the exact order it was transmitted. A CS network relies heavily on error control coding to protect messages from errors in transmission. In general, CS networks work well for voice communications but are not well-suited for certain types of data services.
In a packet-switched (PS) network, a dedicated connection is not required. Instead of a dedicated connection that is allocated for the duration of a call, a PS network breaks the message into packets and transmits each packet individually over the network. Each packet contains routing information and is individually routed over the network to the final destination. Thus, successive packets in the same message may arrive at the final destination through different routes. If some packets get lost during transmission, there is sufficient redundancy to allow the entire message to be reconstructed at the final destination. Because a dedicated connection is not required, packet-switched networks are sometimes referred to as being connectionless. While requiring more overhead to transmit each packet, a packet-switched network does not tie up system resources and a call set-up procedure is not required. PS networks are ideal for data communications, particularly data communications of a bursty nature, such as Internet browsing.
A Class B mobile terminal is defined as a terminal that may connect to a conventional, CS network for voice communications, or to PS network for data communications. For data services, the mobile terminal registers with the PS network in order to receive packet data services, also known as datagram services, and then camps on a control channel called the Packet Common Control Channel (PCCCH). After registration with the PS network, the mobile terminal may also register with a conventional CS network for voice communications while still camping on the PCCCH. Registration with the CS network may be accomplished through a tunneled connection between the PS network and the CS network. After registration, paging messages originating in the CS network are routed via the PS network and transmitted to the mobile terminal on the PCCCH.
Currently, broadcast teleservices are not provided on the PCCCH. Broadcast teleservice is provided only on the DCCH in the CS mobile communication network. Thus, when a Class B mobile terminal is camping on the PCCCH, it is unable to receive BATS-based broadcast teleservice messages.